Herein we report a covalent cage TPE-Zn_(4)based on a tetraphenylethylene molecule via subcomponent self-assembly,which is templated by zinc ions.TPE-Zn_(4)features a quadrangular prismatic cage structure,which is cha...Herein we report a covalent cage TPE-Zn_(4)based on a tetraphenylethylene molecule via subcomponent self-assembly,which is templated by zinc ions.TPE-Zn_(4)features a quadrangular prismatic cage structure,which is characterized by NMR,mass spectrum,and single-crystal X-ray diffractions.TPE-Zn_(4)emitted orange fluorescence(λ_(em)=620 nm)in DMSO solution under the irradiation of UV light(λ_(ex)=395 nm)and can be applied as a fluorescence sensor for selectively detecting Pd^(2+).The fluorescence of TPE-Zn_(4)was quenched by Pd^(2+)in DMSO solution,and a very low detection limit of 62.3 n M was achieved.Mechanism studies reveal that the Pd^(2+)can replace the Zn^(2+),and the heavy atom effect and chelation-enhanced quenching effect between the Pd^(2+)and the cage probably cause the fluorescence quenching.展开更多
An optimized and validated spectrophotometric method has been developed for the determination of cefixime in pharmaceutical formulations. The method is based on the complexa- tion reaction between cefixime and palladi...An optimized and validated spectrophotometric method has been developed for the determination of cefixime in pharmaceutical formulations. The method is based on the complexa- tion reaction between cefixime and palladium ion in the presence of acidic buffer solution （pH 3） in ethanol-distilled water medium at room temperature. The complex absorbed maximally at 352 nm. Beer＇s law is obeyed in the working concentration range of 2.5-35 μg/mL with apparent molar absorptivity of 1.015×104 L/mol cm and Sandell＇s sensitivity of 0.001 μg/cm2/0.001 absorbance unit. The limits of detection and quantitation for the proposed method are 0.175 and 0.583μg/mL, respectively. The effect of common excipients used as additives has been studied in the determination of cefixime. The proposed method has been successfully applied for the determina- tion of cefixime in pharmaceutical formulations. The results obtained by the proposed method were statistically compared with the reference method using t and F values and found no significant difference between the two methods.展开更多
基金supported by the National Natural Science Foundation of China(Nos.21731002,21871172 and 22171106)the Guangdong Major Project of Basic and Applied Research(No.2019B030302009)+4 种基金the Fundamental Research Funds for the Central Universities(No.21622103)Guangdong Natural Science Foundation(No.2022A1515011937)Guangzhou Science and Technology Program(No.202002030411)the China Postdoctoral Science Foundation(No.2022M711327)Jinan University。
文摘Herein we report a covalent cage TPE-Zn_(4)based on a tetraphenylethylene molecule via subcomponent self-assembly,which is templated by zinc ions.TPE-Zn_(4)features a quadrangular prismatic cage structure,which is characterized by NMR,mass spectrum,and single-crystal X-ray diffractions.TPE-Zn_(4)emitted orange fluorescence(λ_(em)=620 nm)in DMSO solution under the irradiation of UV light(λ_(ex)=395 nm)and can be applied as a fluorescence sensor for selectively detecting Pd^(2+).The fluorescence of TPE-Zn_(4)was quenched by Pd^(2+)in DMSO solution,and a very low detection limit of 62.3 n M was achieved.Mechanism studies reveal that the Pd^(2+)can replace the Zn^(2+),and the heavy atom effect and chelation-enhanced quenching effect between the Pd^(2+)and the cage probably cause the fluorescence quenching.
文摘An optimized and validated spectrophotometric method has been developed for the determination of cefixime in pharmaceutical formulations. The method is based on the complexa- tion reaction between cefixime and palladium ion in the presence of acidic buffer solution （pH 3） in ethanol-distilled water medium at room temperature. The complex absorbed maximally at 352 nm. Beer＇s law is obeyed in the working concentration range of 2.5-35 μg/mL with apparent molar absorptivity of 1.015×104 L/mol cm and Sandell＇s sensitivity of 0.001 μg/cm2/0.001 absorbance unit. The limits of detection and quantitation for the proposed method are 0.175 and 0.583μg/mL, respectively. The effect of common excipients used as additives has been studied in the determination of cefixime. The proposed method has been successfully applied for the determina- tion of cefixime in pharmaceutical formulations. The results obtained by the proposed method were statistically compared with the reference method using t and F values and found no significant difference between the two methods.
